Energy transfer apparatus and method of use

Abstract

Energy transfer apparatus such as a viscous damper or hydraulic cylinder apparatus are described along with their use, the apparatus generating velocity dependent damping force between two spatially separate points. The apparatus may comprise a system with a piston coupled to a rod shaft, the piston and rod shaft moving in a fitted, or sealed cylinder with end caps and fluid sealing elements at either end of the cylinder, the system containing fluid in at least one cavity located between the piston and cylinder and an accumulator fluidly connected to the at least one cavity. The rod shaft and piston move relative to the cylinder in the event of an imposed dynamic force and the accumulator counteracts over or under pressure in the at least one cavity.

What is claimed is: 
     
         1 . An energy transfer apparatus comprising:
 a system with a piston coupled to a rod shaft, the piston and rod shaft moving in a fitted, or sealed cylinder with end caps and fluid sealing elements at either end of the cylinder, the system containing fluid in at least one cavity located between the piston and cylinder and an accumulator fluidly connected to the at least one cavity;   wherein the rod shaft and piston move relative to the cylinder in the event of an imposed dynamic force; and   wherein the accumulator counteracts over or under pressure in the at least one cavity caused by:   (a) dynamic forces and/or thermal dissipation effect resulting from the oscillatory force and movement of the rod shaft and piston; as well as   (b) volume changes caused by environmental temperature change imposed on the system while in a static position.   
     
     
         2 . The energy transfer apparatus as claimed in  claim 1  wherein the accumulator is at least partly incorporated into the rod shaft. 
     
     
         3 . The energy transfer apparatus as claimed in  claim 1  or  claim 2  wherein the accumulator is fully integrated into the rod shaft. 
     
     
         4 . The energy transfer apparatus as claimed in any one of the above claims wherein the accumulator comprises at least one gallery within the rod shaft in fluid communication with the at least one fluid cavity. 
     
     
         5 . The energy transfer apparatus as claimed in any one of the above claims wherein the gallery opens to a fluid reservoir inside the rod shaft. 
     
     
         6 . The energy transfer apparatus as claimed in any one of  claims 1  to  4  wherein the gallery opens to a fluid reservoir outside the rod shaft. 
     
     
         7 . The energy transfer apparatus as claimed in  claim 5  or  claim 6  wherein the reservoir is volume variable by a movable piston sealingly located with the reservoir. 
     
     
         8 . The energy transfer apparatus as claimed in  claim 7  wherein the movable piston is biased to maintain a predetermined pressure of fluid in the accumulator. 
     
     
         9 . The energy transfer apparatus as claimed in  claim 8  wherein the bias is selected from a spring and/or a sealed gas cavity. 
     
     
         10 . The energy transfer apparatus as claimed in  claim 5  or  claim 6  wherein the reservoir comprises a tank with a feed hose positioned below the fluid level at all times during operation, the accumulator action being through the raising and lowering of the fluid level in the reservoir. 
     
     
         11 . The energy transfer apparatus as claimed in  claims 2  to  6  and  claim 10  wherein the fluid volume in the reservoir is varied by a pressure imposing means selected from: a free-surface gas volume, gas bladder, bellows, closed cell foam, and combinations thereof. 
     
     
         12 . The energy transfer apparatus as claimed in any one of the above claims wherein the accumulator is in constant communication with the fluid in the at least one cavity. 
     
     
         13 . The energy transfer apparatus as claimed in any one of the above claims wherein the apparatus comprises at least one valve member that maintains communication between the accumulator and a lower pressure cavity or cavities during static and/or dynamic operation. 
     
     
         14 . The energy transfer apparatus as claimed in  claim 13  wherein the at least one valve member is located on the piston. 
     
     
         15 . The energy transfer apparatus as claimed in  claim 13  or  claim 14  wherein the at least one valve member is at least one inverse shuttle valve. 
     
     
         16 . The energy transfer apparatus as claimed in  claim 14  or  claim 15  wherein the at least one valve member is an interlock between two check valves. 
     
     
         17 . The energy transfer apparatus as claimed in  claim 16  wherein the interlock is formed from connected check valves so the valves oppositely close and open in unison. 
     
     
         18 . The energy transfer apparatus as claimed in  claim 16  wherein the interlock is formed from unconnected check valves spaced so they close in unison but open independently. 
     
     
         19 . The energy transfer apparatus as claimed in  claim 17  or  claim 18  wherein the valve only partially closes thereby restricting flow but not stopping flow of fluid across the check valve. 
     
     
         20 . The energy transfer apparatus as claimed in any one of  claims 16  to  19  wherein the check valve stroke length is varied to alter switch phasing. 
     
     
         21 . The energy transfer apparatus as claimed in any one of  claims 13  to  20  wherein the piston and rod shaft have sufficient inertia to urge dynamic switching of the at least one valve member in the event of an imposed dynamic force on the piston and rod shaft. 
     
     
         22 . The energy transfer apparatus as claimed in any one of  claims 13  to  21  wherein the at least one valve member is biased to limit the onset of the valve action below a threshold pressure gradient. 
     
     
         23 . The energy transfer apparatus as claimed in any one of the above claims wherein the rod shaft moves axially within the cylinder. 
     
     
         24 . The energy transfer apparatus as claimed in any one of the above claims wherein the imposed dynamic force is an oscillatory force. 
     
     
         25 . The energy transfer apparatus as claimed in any one of the above claims wherein the piston is a single sided piston with viscous fluid located on only one side of the piston. 
     
     
         26 . The energy transfer apparatus as claimed in any one of  claims 1  to  24  wherein the piston is a double sided piston with viscous fluid located on both sides of the piston. 
     
     
         27 . The energy transfer apparatus as claimed in any one of the above claims wherein bearing elements are present in the end caps to support lateral loads between the cylinder and the rod shaft. 
     
     
         28 . The energy transfer apparatus as claimed in any one of the above claims wherein the rod shaft runs the full length of the cylinder. 
     
     
         29 . The energy transfer apparatus as claimed in any one of the above claims wherein the piston is coupled to at least one rod shaft directly or indirectly via at least one fastener. 
     
     
         30 . The energy transfer apparatus as claimed in any one of the above claims wherein the piston is coupled to the rod shaft by interference fitting the piston to the rod shaft at a point along the rod shaft longitudinal axis. 
     
     
         31 . The energy transfer apparatus as claimed in  claim 30  wherein a force imposed on the rod shaft is transferred to the piston or a force on the piston is transferred to the rod shaft via the friction effect of the interference fit. 
     
     
         32 . The energy transfer apparatus as claimed in  claim 30  or  31  wherein the piston is interference fitted about two rod shaft endings, the first and second rod shafts jointly spanning the full length of the cylinder. 
     
     
         33 . The energy transfer apparatus as claimed in any one of the above claims wherein at least one interference fit ring is used to increase coupling between the rod shaft and piston. 
     
     
         34 . The energy transfer apparatus as claimed in any one of the above claims wherein the at least one cavity pressure imposes a coupling force between the piston and rod shaft. 
     
     
         35 . An energy transfer apparatus comprising:
 a system with a piston coupled to a rod shaft, the piston and rod shaft moving in a fitted cylinder with end caps and fluid sealing elements at either end of the cylinder, the system containing fluid in at least one cavity located between the piston and cylinder and a low pressure accumulator fluidly connected to the at least one cavity;   wherein the rod shaft and piston move relative to the cylinder in the event of an imposed dynamic force; and   wherein the accumulator is at least partly incorporated into the rod shaft and which counteracts over or under pressure in the at least one cavity.   
     
     
         36 . An energy transfer apparatus comprising:
 a system with a piston coupled to a rod shaft, the piston and rod shaft moving in a fitted cylinder with end caps and fluid sealing elements at either end of the cylinder, the system containing fluid in at least one cavity located between the piston and cylinder and a low pressure accumulator fluidly connected to the at least one cavity;   wherein the rod shaft and piston move relative to the cylinder in the event of an imposed dynamic force; and   wherein at least one valve member maintains communication between the accumulator and a lower pressure cavity or cavities during static and dynamic operation.   
     
     
         37 . An energy transfer apparatus comprising:
 a system with a piston coupled to a rod shaft, the piston and rod shaft moving in a fitted cylinder with end caps and fluid sealing elements at either end of the cylinder, the system containing fluid in at least one cavity located between the piston and cylinder and a low pressure accumulator fluidly connected to the at least one cavity;   wherein the rod shaft and piston move relative to the cylinder in the event of an imposed dynamic force; and   wherein at least one valve member maintains communication between the accumulator and a lower pressure cavity or cavities, the at least one valve member being located on and/or within the piston.   
     
     
         38 . An energy transfer apparatus comprising:
 a rod shaft and at least one piston coupled to the rod shaft located about at least a region of the rod shaft longitudinal length, the piston and rod shaft moving in a fitted cylinder; and   wherein:   (a) the rod shaft and piston move relative to the cylinder in the event of an imposed dynamic force; and wherein an accumulator counteracts over or under pressure on one or both sides of the piston; and   (b) the at least one coupled piston is interference fitted to the rod shaft to prevent relative movement between the rod shaft and at least one coupled piston, coupling completed by a combination of:
 i. a clamping force imposed by the at least one coupled element on the shaft due to an imposed interference fit between at least part of the at least one coupled element and the shaft; and 
 ii. a friction effect due to clamping about at least part of the at least one coupled element and the shaft facing surfaces. 
   
     
     
         39 . The energy transfer apparatus as claimed in any one of the above claims wherein the energy transfer apparatus is a viscous damper 
     
     
         40 . The energy transfer apparatus as claimed in any one of the above claims wherein the energy transfer apparatus is a hydraulic cylinder. 
     
     
         41 . A method of damping a dynamic force imposed on a system, the method comprising the step of integrating at least one energy transfer apparatus as claimed in any one of the above claims with the system so as to dampen the oscillation force acting on the system. 
     
     
         42 . The method as claimed in  claim 41  wherein the system is a structural element.